Safety envelope



Nov. 28, 1939. M. voel-:L

' SAFETY ENVELOPE Filed N0`v`. 18, 1953 JN VEN TOR.

Mmcl VCI/3m.. BY

` A TTORNEY Patented Nov. 28, 1939 UNITED STATES PATENT ori-ICEApplication November 18, 1933, Serial No. 698,624 In Germany (ictober10, 1933 3 Claims.

The present invention relates to safety- 4envelopes, particularly of thetype in which cooperating adhesive surfaces are provided on the closingap and upon -anotherportion of the enmoistened, but will firmly stick tothe same ad' hesive substance, a suitable substance of this characterbeing a solution of para rubber in gaso-v line. For convenience thissubstance. because of its property of adhering to itself without thenecessity for moistening it, will hereinafter be l referred to as dryadhesive.

' Envelope structures heretofore in use were for the most partunsatisfactory for the use of suchv` cooperating adhesive surfaces,particularly because of` the fact that the adhesive surfaces would v,20be apt to stick together prematurely, would be exposed to d-ust and dirtwhen they were out of contact with each other with the flap open, and onthe contrary it was not possible to stack the envelopes, or'run them ina printing press or ,1.25 typewriter with the flap closed without theadhesive surfaces becoming stuck together. It `has been proposed'incertain instances lto place a protective strip of removable parailinpaper, cloth, or the like between vthe adhesivesurfaces to preventpremature sticking, but this was-expensive and inconvenient,'and was notreliable as the strip was not a permanent part of the en` velope,and'would be apt to become displaced. vIt

is proposed in thepresent invention to provide a protective iiap for oneof the adhesive surfaces which in one position protects the adhesive'surface of the closing iiap when the latter is folded in superimposedrelation and in another position exposes such adhesive surface, andwhich flap is further adapted to be folded into the envelope about theupper edge of the contents to retain them, and with the closing flapforms a double protective closure means.

Another object is to provide a safety envelope y which will disclose anyattempt to open or tamper I with the envelope. Y, An envelope employingadire-- sive substance of the type proposed herein cainot be opened as`an ordinary gummed flap envelope can by steaming. but can be opened byemploying a suitable solvent for the adhesive substance, as for instancegasoline or alcohol. -It is an object of the present invention toprovide means which .will give anindication if the envelope has beenincontact with such solvent, and to this end I.

s particularly propose to provides. marking which i(Cl. 229-80) whencontacted by such solvent will stain through the paper, spread orotherwise show that the envelope has been tampered wit AWith the aboveand other objects in view an embodiment of the invention isshown in the5 accompanying drawing, and this embodiment will be hereinafter morefully described with reference thereto, and the invention will be nallypointed out in the claims.

lIn the drawing- 10 Fig. 1 is a plan view of the rear side of anenvelope, according to one illustrated exemplary embodiment of theinvention, the same being shown in its unsealed relation.

Fig. 2 is a vertical sectional view, taken along l5 the line 2--2 ofFig. 1, and showing another envelope inthe same relation adjacentthereto.

Fig. 3 is a fragmentary, plan view, with the two aps folded upwardlypreparatory to inserting an enclosure, and showing one of the adhesivesur- 20 faces exposed. l

Fig.v4 is a vertical sectional view taken alongA the line l-l of Fig. 3.

Fig. 5 is a fragmentary plan view, showing the iiap at the upper edge ofthe back portion folded 25 into the envelope about the upper edge of theenclosure. Fig. 6 is a vertical sectional view taken along v the line 06 of Fig. 5, the enclosure being shown in dot-and-dash lines.

Fig. 'l is a fragmentary plan view showing the closing flap closed andsealed.

Fig. 8 is a vertical sectional viewA taken along the line 8 8 of Fig."l, the enclosure being shown in dot-anddash lines. 35

Fig. 9 is a fragmentary plan view showing the manner in which themarking shows when the, envelope has been subjected to a solvent in anunauthorized attempt to open it.

Similar. reference characters indicate corre- 40 spending partsthroughout the several figures of the drawing. Y

Referring to the drawing. the envelope, according to the illustratedexemplary embodiment of .theinventiom comprises a front or address-side46 portion III, side naps I 2-I2 bent inwardly from the side edges ofthe portion I 0, and a back portion il, suitably secured, as by theusual pasting methods, to the side aps. .A closing iiap I3 is 50provided at the upper edge of the front portion I0 and vanother flap Ilis provided at the upper edge of the back portion, the folds of the twoflaps coinciding, and the flap I4 being of such extent as tosubstantially coincide with the nap I3. For

- reversely printed on this purpose it may be of exactly the same sizeor it may be larger. ,f

A strip of dry-adhesive I is provided on the inner side of the flap I3,and a similar strip of dryadhesive I6 is provided on ,the back portionII adjacent its upper edge, and in such relation as to be contacted bythe dry-adhesive IS when the nap I4 is folded in and the closing nap t3folded down, and to be covered by the flap Il when the latter is foldeddownwardly upon the outer' side of the back portion. f

Upon the inner side of the iiap I3 a marking I1 is provided, the sameing or stamping with an ink or other suitable contrastingly coloredsubstance that is soluble in the same substance hat will dissolve theadhesive. Adhesive of the type gasoline or alcohol, and a suitablemarking substance which is also soluble in these liquids is aniline ink.I-have shown the marking in the form of the words This has been tamperedwith, the under side of the flap Il, so that if` subjected to thesolvent after sealing these letters `will stain .through the paper andbe visible as shown in Fig. 9. It will be understood that the marking`may also be in the form of a design, and that it may be placed uponeither or both surfaces of either or both of the flaps I3 and I4, and/orit may be placed upon .either or both of the adhesive strips I5 and Ii.

Before use and when stacked the closing flap I3 and the protective flapupon the back surface, as shown in Figs. 1 and 2, so that both adhesivestrips are concealed and are out of contact lby reason of. theinterposition of the protective flap I4 between them. The envelope maythus be printed upon, inserted in a typewriter, sorted, or'otherwisehandled as an ordinary envelope, as no portion carrying thedry-adhesive strips are exposed. or. disposed in such relation as tovpremature contact each other. To insert an enclosure the flaps areturned upwardly, as indicated in Figa-3 and 4, and 'may both be graspedand spread outwardly, 4thuis widening the opening and providing, formore, convenient insertion of the enclosure than with the usual type 'ofenvelope. Thereupon the lnap Il is folded into the envelope over theupper edge of the enclosure.' thereby retaining and protecting it, asshown in Figs. 5 'and 6, and the closing .flap the adhesive strip I'intocontact with the exposed adhesive strip I8. By slight pressure appliedto the outer side ofthe ap" 'L3 Athe adhesive strips are homogeneously'joined and the envelope is thus sealed. In this latter relation theupper edge of the enclosure -is protected by the double fold of the twoaps.

I have illustrated and described a preferred and satisfactoryembodimentof the invention, but it will be obvious that changesmay bemade therein, Lwithin the spirit and scope thereof( as dened in theappended claims. Having thus described my invention 'what I claim anddesire to secure by- Letters Patent is:

1. In an envelope, front and back portions, a closing flap carried atthe Vupper' edge. of said. front portion and foldable along said edge intwo being produced by printemployed herein is soluble in I4- are bothfolded downA guide surfaces I3 is tlien folded. down bringing o tionsadapted in directions, a second ap carried at the upper edge of saidback yportion and foldable in two directions respectively into contactwith the inner and outer surfaces of. said back portion, both of saidaps being foldable downwardly in overlying relation to the outer sidewhich position said closing flap is adapted to overlie said second flap,an adhesive substance on the inner side of said closing flap, said sidebeing disposed inwardly in said folded-down relation of said flap, anadhesive substance on the outer side of said back arranged to be coveredby said second flap when the latter is folded downwardly upon the outerside of said back portion and to be contacted by said adhesive substanceon the closing flap when said second flap is folded upon the inner sideof said back portion, the adhesive substance pon said closing flapadapted to adhere to the adhesivesubstance upon said back upon contacttherewith.

2. In an envelope, front and back portions, a pair of 4foldable iiaps onthe upper edges of said portions, an adhesive substance upon one side ofone of said flaps, the second nap being free of an adhesive on bothsides and foldable about the. upper edge of the portion ofthe envelopecarrying said second flap from engagement with one surface of theenvelope portion to engagement with the other surface, an adhesivesubstance upon the outer surface of the envelope adapted to be dis'posed andconcealed beneath the second flap in the one folded position ofsaid second ap at one side of said envelope portion and adapted to beexposed in the other folded position of said second flap at the otherside of said envelope portion,' said first-mentioned adhesive substanceadapted to adhere to said second-mentioned adhesive substance uponcontact therewith, said flaps adapted -adhesive substance tosuperimposition of said' other flap thereon with said first-mentionedadhesive substance contacting with said secondmentioned adhesivesubstance.

3. In an envelope, front and back portions, oneA portion having anadhesive section upon one side spaced from its upper edge, a. protectivesection between said adhesive section and said upper edge free of anadhesive on both sides and adapted to be folded upon said adhesivesection to cover it,- the ther portion having an adhesivesection upon'one side adjacent its upper edge, one of said adhesive sections adaptedto be folded upon the other adhesive section, said protective section inone position adapted to be interposed between said adhesive sections,one of said adhesive sec-- another position of said protective sectionto be folded upon the other adhesive section Without said protectivesection interposed v whereby said adhesive sections contact each other,

one adhesive section adapted to adhere to thef other adhesive sectionupon contact therewith.

MAX VOGEL.

